In spring 1942 Hitler decided to fortify the coasts of Western
Europe to prevent an Allied invasion of the continent.

In June 1944 this gigantic fortification line from Norway down
to the Spanish border was still in construction but almost
15.000 bunkers with over 3.000 guns were already finished. This
bulwark, which became famous as the "Atlantic Wall", should
prevent an Allied invasion or, at least, delay it until the
Germans could mobilize sufficient armored forces to defend the
enemy.

The occupied British Channel Islands, the U-Boot bases
and some important harbours formed the cornerstones of the Atlantic Wall.
They were declared to Festungen (fortresses) due to their
importance as possible invasion targets.

The risk of an Allied
invasion on the occupied continent was brought up for discussion
by the German High Command for the first time after the onset of
war of the United States. On December 14, 1941 a Weisung (directive)
was published with the instruction to transform the coasts of
Western Europe from the North Cape in Norway down to the Biskaya
into a "second Westwall". With this directive, the period of an
offensive warfare was officially replaced with a defensive
strategy. The British raid on the village of Dieppe on August
19, 1942 showed very clearly that the fortifications of the
Atlantic Wall were absolutely inevitable to protect against the
Second Front of the Allies.

Propaganda minister Goebbels started a massive propaganda
campaign to show the invincibility of the Atlantic Wall.
Newsreel reports about big offensive gun batteries should
influence the own population as well as the international public
to believe the high fighting strenght of the fortifications. But
reality was completely different: at many places the building
sites suffered under amorphousness, scramble for authority and
supply difficulties. This was even intensified with the
increasing Allied air power.

The coastal artillery was formed by 28 different calibres from
7,5-cm to 40,6-cm. Even naval guns, Sowjet, French or Czech guns
and old models of World War One made part of the armament.

The German High Command expected the Allied invasion on the
shortest place of the Channel, the so called Pas de Calais. Most
of the German fortifications were build up here. Some remote
areas were less fortified or even unprotected. This was also the
case in the Seine bay between Le Havre and Cherbourg. This
sector was only guarded by 47 gun batteries (compared to 132 in
the Pas de Calais area).

Nobody knew the weaknesses of the Atlantic Wall better than
Field Marshal Rommel. He became the Chief inspector of the
coastal defences in the West in late 1943 and he was convinced
that an Allied landing could only be defeated in the first 48
hours. Against time he made every effort to plug the gaps he had
identified in the Atlantic Wall and ordered to fortify the
coasts and the back up area. Meadows and fields were covered
with mine posts against air landings and the beaches were
protected with thousand of obstacles against landing ships.

Contrary to all expectations, the Allies did not only land in an
unex-pected area, but also at an unexpected point of time: it
was the early morning of June 6, 1944 when D-Day took place at
the beaches of Normandy. Due to their overall sea and air power
the troops could break through the Atlantic Wall at four of the
five landing sectors on the first day of the invasion. Cherbourg
and Le Havre, the two big harbours, were forced to surrender
after the consolidation of the beachheads.